I just removed my air-cond from my 1966 Fastback and i am in the process of getting my Engine Compartment dialed in and wondering if anybody makes a grommet or a plug for the hole in the firewall? if not i guess i could get a good size piece of rubber and fashion my own if needed. thanx

 

I think that Mustangs Unlimited and CJ Pony have that firewall grommet. I got a new one from one of them.